1. Field of the Invention
The present invention pertains to a mounting support for electrical switches and legend plates associated therewith, that are mounted on an indicator board, wherein the switches include a housing and a housing cover, the latter adjoining the back face of the indicator board, with the housing and the housing cover being bolted to the indicator board.
2. Discussion of the Background of the Invention and Material Information
Electric switches, for example in the form of push button switch assemblies, are often used in elevators, where they are utilized in the cars as car call transmitters or are utilized at the floors as floor call transmitters. The push button switch assemblies and the associated legend plates, that is the legend plates showing the respective floor number, are attached at an indicator board. The push button switch assemblies used for these purposes are, due to frequent actuation by elevator users, exposed to high loads or stresses, so that they must be built correspondingly ruggedly. In addition, these switches and legend plates must be attached at the indicator board in a manner such that unintended damages or damages caused by vandalism can be avoided.
The push button switch assembly set forth in U.S. Pat. No. 4,504,713 fulfills the previously noted requirements and includes a housing and a housing cover, the latter directly adjoining the rear face of the indicator board. The housing cover includes an annular projection, whose height is substantially the same as the thickness of the indicator board, which engages with a circular cutout of the indicator board. The push button of the push button switch assembly is slidably guided, in a bore concentric with the annular projection, in a manner such that the push button does not extend beyond the indicator board. The housing and the housing cover are provided with overlapping bosses having apertures for the reception of threaded bolts which in turn are welded onto the indicator board and serve for the attachment of the push button switch assembly.
Though not further described in the previously noted patent, adjacent to the push button switch assembly, a legend plate is also commonly attached to the indicator board. The legend plate can take the form of a thin, rectangular, metal plate having a threaded bolt welded thereto for attachment purposes. The inscription on the legend plate is for example, the number of the respective floor. The indicator board includes a rectangular recess, produced generally via embossing or pressing, of the size of the legend plate, and a smaller substantially rectangular cutout, within the recess, whose side edges are provided with ledges or protrusions. This recess is so dimensioned however that the legend plate does not extend beyond the front plate. The ledges serve for the location and support of a washer shoved over the threaded bolt during the attachment of the legend plate.
A particular drawback of the previously described attachment manner of the legend plate lies in that, for the manufacture of the recess and the cutout, several working steps are required that must be carried out on different machines, thus incurring relatively high production costs.